An aqueous solution of urea had a freezong point of -0.40 celsius. Calculate the osmostic pressure of the same solution at 37 C. Asume that the molarity and molality are numerically equal.

Asked by lekhakarthikeyan | 29th Aug, 2018, 08:08: PM

Expert Answer:

 
Given:
 
Freezing space point space of space solvet space equals space straight T to the power of 0

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space straight T to the power of 0 space equals space space space 0 to the power of ring operator straight C space equals 273 space straight K

Freezing space point space of space solution space equals straight T subscript straight f

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space straight T subscript straight f equals space minus 0.40 to the power of ring operator straight C
space space space space space space space space space space space space space space space space space space space space
space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals space 273 minus 0.40 space equals space 272.6 space straight K

Depression space in space freezing space point space increment straight T subscript straight f space equals space space straight T to the power of 0 minus space straight T subscript straight f

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals space 273 minus space 272.6

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space increment straight T subscript straight f equals space 0.4 space straight K

We space have comma

space space increment straight T subscript straight f space equals space straight K subscript straight f space cross times space straight m space space space space space space space

For space water space space straight K subscript straight f space equals 1.86 space

straight m equals fraction numerator increment straight T subscript straight f over denominator straight K subscript straight f space end fraction space space space space space space space

space space space equals fraction numerator 0.4 space over denominator 1.86 end fraction

straight m equals space 0.2150 space straight m

Osmotic space pressure space straight pi space equals CRT space space

straight C equals space molarity space equals space molality

straight R space equals space 0.083 space litre space atm divided by straight K

straight T space equals space 37 plus 273

space space space equals space 300 space straight K

straight pi space equals space 0.2150 cross times 0.083 cross times 300

straight pi space equals space 5.35 space atm

space space space space space space space space space space space space space
Osmotic pressure is 5.35 atm
 

Answered by Varsha | 3rd Sep, 2018, 07:14: PM